Rechargeable battery pack

Abstract

A rechargeable battery pack is disclosed. In one aspect, the rechargeable battery pack includes a holder accommodating a plurality of unit cells, wherein each unit cell includes a rechargeable battery, and a case accommodating the holder. The case includes a bottom portion and a cover placed over the bottom portion and the holder. The holder includes a plurality of protrusions that protrude toward the bottom portion and the bottom portion has a plurality grooves defined to respectively correspond to the protrusions.

What is claimed is: 
     
       1. A rechargeable battery pack, comprising:
 a holder accommodating a plurality of unit cells, wherein each unit cell includes a rechargeable battery; and 
 a case accommodating the holder and comprising i) a bottom portion and ii) a cover placed over the bottom portion and the holder, 
 wherein the holder includes a plurality of protrusions that protrude toward the bottom portion, 
 wherein the bottom portion has a plurality grooves defined to respectively correspond to the protrusions, 
 wherein each of the unit cells has a substantially cylindrical shape, 
 wherein the holder includes a plurality of receiving portions respectively configured to accommodate the unit cells, 
 wherein the protrusions are divided into pairs, 
 wherein the protrusions of each pair are formed on different sides of a corresponding one of the receiving portions, 
 wherein the receiving portions are arranged in a first direction, and 
 wherein each pair of protrusions is arranged in the first direction. 
 
     
     
       2. The rechargeable battery pack of  claim 1 , wherein each of the receiving portions includes i) a pair of cylinder portions formed on opposing ends thereof and ii) a semi-circular portion connecting the pair of cylindrical portions and having a shape corresponding to one side of the unit cell. 
     
     
       3. The rechargeable battery pack of  claim 2 , wherein each of the protrusions protrudes from one of the cylinder portions and wherein each of the grooves accommodates the corresponding protrusion. 
     
     
       4. The rechargeable battery pack of  claim 1 , wherein each of the protrusions includes an inclined portion that extends toward the bottom portion at an angle and a horizontal portion that: i) extends from the inclined portion, ii) is substantially parallel to the bottom portion and iii) is configured to be caught by the corresponding groove. 
     
     
       5. The rechargeable battery pack of  claim 4 , wherein each of the grooves includes a catching protrusion configured to: i) guide the horizontal portion of the corresponding protrusion when it is inserted into the groove and ii) catch the inserted horizontal portion of the corresponding protrusion so as to prevent the horizontal portion from being separated therefrom and wherein each of the connective grooves defines a recess space formed below the catching protrusion and wherein each of the protrusions is configured to rotate within the corresponding recess space when being inserted into the groove. 
     
     
       6. The rechargeable battery of  claim 5 , wherein each of the recess spaces has a substantially semi-circular shape. 
     
     
       7. A rechargeable battery pack, comprising:
 a holder accommodating a plurality of unit cells, wherein each unit cell includes a rechargeable battery; and 
 a case accommodating the holder and comprising i) a bottom portion and ii) a cover placed over the bottom portion and the holder, 
 wherein the holder includes a plurality of protrusions that protrude toward the bottom portion, 
 wherein the bottom portion has a plurality grooves defined to respectively correspond to the protrusions, 
 wherein each of the protrusions is formed only at one side of each cylinder portion, 
 wherein each of the protrusions includes: i) an inclined portion that extends toward the bottom portion at an angle and ii) a horizontal portion that extends from the inclined portion and is substantially parallel to the bottom portion, and 
 wherein each of the grooves defines a space having substantially the same shape as that of the corresponding protrusion. 
 
     
     
       8. A rechargeable battery pack, comprising:
 a holder accommodating a plurality of unit cells, wherein each unit cell includes a rechargeable battery; and 
 a case accommodating the holder and comprising i) a bottom portion and ii) a cover placed over the bottom portion and the holder, 
 wherein the holder includes a plurality of protrusions that protrude toward the bottom portion, 
 wherein the bottom portion has a plurality grooves defined to respectively correspond to the protrusions, 
 wherein each of the unit cells has a substantially cylindrical shape, 
 wherein the holder includes a plurality of receiving portions respectively configured to accommodate the unit cells, 
 wherein each of the receiving portions includes i) a pair of cylinder portions formed on opposing ends thereof and ii) a semi-circular portion connecting the pair of cylindrical portions and having a shape corresponding to one side of the unit cell, 
 wherein the holder further includes a plurality of ribs that protrude toward the bottom portion between the receiving portions and wherein the ribs are supported by the bottom portion, and 
 wherein each of the ribs protrudes from a corresponding one of the semi-circular portions between the corresponding pair of cylinder portions. 
 
     
     
       9. The rechargeable battery pack of  claim 8 , wherein the bottom portion further includes a plurality of secondary grooves respectively corresponding to the ribs and wherein the secondary grooves accommodate portions of the corresponding ribs. 
     
     
       10. The rechargeable battery pack of  claim 1 , wherein the holder is configured to be inserted into the bottom portion of the case in a direction substantially perpendicular to the bottom portion. 
     
     
       11. A rechargeable battery pack, comprising:
 a plurality of rechargeable battery cells; 
 a holder housing the rechargeable battery cells and including a plurality of first protrusions; and 
 a case housing the holder and including a bottom portion having a plurality of grooves defined to respectively correspond to the first protrusions, 
 wherein the first protrusions are connected to the bottom portion via the respective grooves, and 
 wherein each of the first protrusions includes: i) an inclined portion extending toward the bottom portion at an angle and ii) a horizontal portion extending from the inclined portion and formed substantially parallel to the bottom portion. 
 
     
     
       12. The rechargeable battery pack of  claim 11 , wherein each of the grooves includes: i) a recess space and ii) a second protrusion formed over the recess space and configured to engage with at least a portion of the corresponding horizontal portion. 
     
     
       13. The rechargeable battery pack of  claim 12 , wherein each of the second protrusions is configured to deform the corresponding first protrusion when the first protrusion is inserted into the groove and wherein each of the first protrusions is configured to rotate within the corresponding recess space during the insertion. 
     
     
       14. The rechargeable battery pack of  claim 12 , wherein each of the recess spaces has a substantially semi-circular shape. 
     
     
       15. The rechargeable battery pack of  claim 11 , wherein the holder includes a plurality of receiving portions respectively housing the rechargeable battery cells and wherein each of the receiving portions includes i) a pair of cylinder portions formed on opposing ends thereof and ii) a semi-circular portion connecting the pair of cylindrical portions and having a shape corresponding to one side of the rechargeable battery.